1. Field of the Invention
The present invention relates to a fuel injection valve which includes a coil, a core having an end thereof arranged at an inner side of the coil, a body having an end thereof fixedly secured to the end of the core at an inner side of the coil, and an armature arranged at an inner side of the body, and also relates to a method for manufacturing such a fuel injection valve.
2. Description of the Related Art
In the past, there has been known a fuel injection valve which includes: a coil that is adapted to be energized to generate a magnetic field; a core that has an end arranged at an inner side of the coil and is magnetized by the magnetic field generated by the coil; a cylindrical body that is made of a magnetic material, has an end thereof fixedly attached to the end of the core at an inner side of the coil, and is arranged so as to cover an axial end portion of the coil and in abutment with a cylinder head of an engine; a housing of a cylindrical shape that is made of a magnetic material, is arranged at an outer side of the coil, and has an end portion thereof fixedly attached to the body; a cap that is made of a magnetic material, is fixedly attached to the other end of the housing, is also fixedly attached to the core so as to cover the other axial end of the coil, and is arranged in abutment with a fastening unit from a side opposite to the housing side; and an armature that is arranged at an inner side of the body so as to be movable for reciprocation, and is adapted to be magnetically attracted to the magnetized core; wherein the fuel injection valve is mounted on the engine with the body and the cap being arranged in abutment with the cylinder head and the fastening unit, respectively (see, for example, a first patent document: Japanese patent application laid-open No. 2007-16774).
In this case, however, when the fuel injection valve is mounted on the engine, the body and the cap are subjected to a compression force acting in an axial direction from the cylinder head and the fastening unit, but since the core is fixedly attached to the cap, the body and the core are caused to deform in a direction to move toward each other, whereby the distance between the armature and the core at the time of the non-energization of the coil becomes narrower than a desired distance. As a result, there has been a problem that it is impossible to obtain a desired flow rate of fuel injected from the fuel injection valve.